Enter into the darkness those (fools) who engage into the activities of destruction (by creating conflict based on ideology, likes, race or origin), yet enter into greater darkness those who engage into (selfish ) the lust of material gatherings. Or Enter into the darkness those who renounce the world or disregard this material existence but yet enter into more darkness those who deeply indulge into material lust.
This meaning appears most suitable. What this shloka says is one of the core principles ofSanatan Dharma. Vedas and all other scriptures tell human to follow the Karma and renounce only the fruits of the karma and not the karma. Human should renounce the lust, the greed and the fruits of Karma. Karma can never be renounced. In Shrimad Bhagvad Gita, Bhagvan Shri Krishna very clearly given this principle fo Sanyas and Karma Yoga by explaining that Karma is the core of living existence and material body has its own significance. One should renounce the fruits of actions and not the actions itself. Rather this very principle is called as “Sanyas” Please find the following references:
Shrimad Bhagvad Gita Ch3:Sh4 na karmanam anarambhan naiskarmyam puruso ‘snute na ca sannyasanad eva siddhim samadhigacchati
Not by merely abstaining from work can one achieve freedom from reaction, nor by renunciation alone can one attain perfection.
Ch18:Sh5 yajna-dana-tapah-karma na tyajyam karyam eva tat yajno danam tapas caiva pavanani manisinam
Sacrifice,charity, austerity and penance are not to be given up but are to be performed. Yajna(Making sacrifice), charity and performing penance even purifies a wise men.
Shri Bhagvan Said Giving up activities that are based on the material desire is called the Sanyas.
The material world, The karma can never be renounced but then one should not be attached to it either. One should do all his material duty but renounce just the fruits of the same. This is called Sanyas and Sanyas is the core principle of Sanatan Dharma.
The above shloka of Yajurveda#40.9 tells the same thing. A human should never disregards the material body or existence(Asambhooti : असम्भूति) but he should not develop lust to material world and engage into amassing wealth, gathering material objects either(Sambhooti:सम्भूति). Such is the path of sorrow, the Darkness.
Truth is the biggest way to counter lies and hence we should all be well informed. “Om Shanti Shanti Shanti “