Back now and here is what I make of the shabad in question in its entirety, Shanger ji.
All the elements of the Bhakti devotional tradition are found in the shabad. When you read through you can see these principles of Bhakti enunciated in the Gitas:
(Verse. 3) “Those who search my imperishable, invisible, unmanifest, omnipresent, beyond the limits of imaginations and yet permanent and hidden form (Spirit or soul) are also my devotees”. (V-3). For such devotees Lord indicates a three point plan (formula or path) in verse N0. 4.
(Verse. 4) “Those who search me via search of self (Atman) and soul can also see me in following way: (1) They have to control 10 organs- 5 sense organs and 5 organs of actions, plus mind and intellect; (2) They have to develop an attitude of equality for all living beings, (namely all living human beings, animals and plants) (3) They have to ever remain active in benevolent deeds for the welfare of all beings and creations during their entire life. Then such devotees can see my infinite form”. (V-4).
So how do we find this in the shabad of Sant Namdev.
Stanzas 1 and 2 Namdev threatens
his tongue with physical harm. He is actually speaking to all of us. This is only figuratively a threat, of course. Taste is one of the senses and the tongue is the organ for taste, and ultimately over indulgence in food. He says to his tongue, " Chant," do immerse yourself, Tongue, in devotion to sri govind, instead, because sri govind is the wondrous seed of the universe. Govind also stands for spiritual wisdom.
ਰੇ ਜਿਹਬਾ ਕਰਉ ਸਤ ਖੰਡ ॥
rae jihabaa karo sath khandd ||
O my tongue, I will cut you into a hundred pieces,
ਜਾਮਿ ਨ ਉਚਰਸਿ ਸ੍ਰੀ ਗੋਬਿੰਦ ॥੧॥
jaam n oucharas sree gobindh ||1||
if you do not chant the Name of the Lord. ||1||
Stanzas 3 and 4, Namdev says the tongue (all of us) should instead be "imbued" / drenched in the name of Hari, the Lord. The rehao line makes more obvious that not only the tongue but all of our consciousness should be imbued with the "this most excellent color" /meaning dyed with the love of Haree.
ਰੰਗੀ ਲੇ ਜਿਹਬਾ ਹਰਿ ਕੈ ਨਾਇ ॥
rangee lae jihabaa har kai naae ||
O my tongue, be imbued with the Lord's Name.
ਸੁਰੰਗ ਰੰਗੀਲੇ ਹਰਿ ਹਰਿ ਧਿਆਇ ॥੧॥ ਰਹਾਉ ॥
surang rangeelae har har dhhiaae ||1|| rehaao ||
Meditate on the Name of the Lord, Har, Har, and imbue yourself with this most excellent color. ||1||Pause||
Stanzas 5 and 6. Here again the tongue is used only as metaphor for all of our body and mind. We have a tendency to busy ourselves with the material world and our false views of reality, Maya. If the tongue (we) were to recite the name of the One God Haree, then the tongue (we) would achieve consciousness of God, become Godly. It is only through this meditation, according to the bhagats of Nam Dev's time, that one achieves nirvana, or the "step" of nirvana which is the stage at which a devotee achieves realization of God. Everything else is false.
ਮਿਥਿਆ ਜਿਹਬਾ ਅਵਰੇਂ ਕਾਮ ॥
mithhiaa jihabaa avaraen kaam ||
O my tongue, other occupations are false.
ਨਿਰਬਾਣ ਪਦੁ ਇਕੁ ਹਰਿ ਕੋ ਨਾਮੁ ॥੨॥
nirabaan padh eik har ko naam ||2||
The state of Nirvaanaa comes only through the Lord's Name. ||2||
Stanza 7 and 8. Bhagat Namdev teaches that all other forms of worship and "devotion" or pooja are nothing compared to total devotion and immersion in the Naamai Haree, God's name.
ਅਸੰਖ ਕੋਟਿ ਅਨ ਪੂਜਾ ਕਰੀ ॥
asankh kott an poojaa karee ||
The performance of countless millions of other devotions
ਏਕ ਨ ਪੂਜਸਿ ਨਾਮੈ ਹਰੀ ॥੩॥
eaek n poojas naamai haree ||3||
is not equal to even one devotion to the Name of the Lord. ||3||
Stanzas 9. Namdev says this is his one and only blessed deed or karanaa - to be a faithful devotee of God.
ਪ੍ਰਣਵੈ ਨਾਮਦੇਉ ਇਹੁ ਕਰਣਾ ॥
pranavai naamadhaeo eihu karanaa ||
Prays Naam Dayv, this is my occupation.
Stanza 10 Namdev says God/Haree your forms are endless/naaraaeinaa.
ਅਨੰਤ ਰੂਪ ਤੇਰੇ ਨਾਰਾਇਣਾ ॥੪॥੧॥
ananth roop thaerae naaraaeinaa ||4||1||
O Lord, Your Forms are endless. ||4||1||
Stanza 11 and 12. He then gives the moral teaching consistent with the Bhakti philosophy. Those of us who give up greed and lust, those are the ones who are able to take refuge in Haree.
ਪਰ ਧਨ ਪਰ ਦਾਰਾ ਪਰਹਰੀ ॥
par dhhan par dhaaraa pareharee ||
One who stays away from others' wealth and others' spouses
ਤਾ ਕੈ ਨਿਕਟਿ ਬਸੈ ਨਰਹਰੀ ॥੧॥
thaa kai nikatt basai nareharee ||1||
- the Lord abides near that person. ||1||
Stanzas 13 and 14 Namdev speaks to those who do not "meditate and vibrate"/actually sing bhajans (bhajanthae). Bhajans are mantras in praise of a deity and are set to music and meant to be sung in sangat. The verse in English says, "I do not want to see them." This means, however, to those people I will not give darshan (Namdev will only give darshan to those who are serious about their devotion.) This is a second rehao line and is therefore very important. It is important to remember that Namdev is writing this as if he is the one who is speaking it. However, he is actually stating that those who are not faithful and devout will not receive darshan of Haree. In the end, they will not achieve God Conciousness.
ਜੋ ਨ ਭਜੰਤੇ ਨਾਰਾਇਣਾ ॥
jo n bhajanthae naaraaeinaa ||
Those who do not meditate and vibrate on the Lord
ਤਿਨ ਕਾ ਮੈ ਨ ਕਰਉ ਦਰਸਨਾ ॥੧॥ ਰਹਾਉ ॥
thin kaa mai n karo dharasanaa ||1|| rehaao ||
- I do not even want to see them. ||1||Pause||
Stanza 15 and 16 He says that if someone cannot be in harmony, in tune, with the divine, that person then still possesses an animal nature. In other words, it is only through faith, devotion and consciousness of the divine that we become truly human.
ਜਿਨ ਕੈ ਭੀਤਰਿ ਹੈ ਅੰਤਰਾ ॥
jin kai bheethar hai antharaa ||
Those whose inner beings are not in harmony with the Lord,
ਜੈਸੇ ਪਸੁ ਤੈਸੇ ਓਇ ਨਰਾ ॥੨॥
jaisae pas thaisae oue naraa ||2||
are nothing more than beasts. ||2||
Stanzas 17 and 18. This image of the nose and the beauty marks is very much a powerful teaching of an important idea in the Bhakti movement. A man without a nose cannot breathe properly. The nose in this stanza is the organ that brings in air, which is the pranayam, or spiritual energy. The 32 beauty marks refer to the 32 qualities that Hindus believed were evidence of a moral nature. A person could have only a few indicators of a moral life, or all 32. But Namdev is saying that even this is academic. Even a moral person must imbue the essence of Haree through devotion.
ਪ੍ਰਣਵਤਿ ਨਾਮਦੇਉ ਨਾਕਹਿ ਬਿਨਾ ॥
pranavath naamadhaeo naakehi binaa ||
Prays Naam Dayv, a man without a nose
ਨਾ ਸੋਹੈ ਬਤੀਸ ਲਖਨਾ ॥੩॥੨॥
naa sohai bathees lakhanaa ||3||2||
does not look handsome, even if he has the thirty-two beauty marks. ||3||2||
In one sentence, Bhagat Nam Dev is saying if you do not give up your indulgence in the material world of sensation, and drench yourself in devotion to the naam, you never will achieve the state of god consciousness. Hope that helps with your question.