Tafsir of Ad-Dukhan 44:3

إنا أنزلناه في ليلة مباركة

We sent it down on a blessed night. Allah tells us that He revealed the Magnificent Qur'an on a blessed night, Laylatul-Qadr (the Night of Decree), as He says elsewhere:

إنا أنزلنه فى ليلة القدر

Verily, We have sent it down in the Night of Al-Qadr, (97:1) This was in the month of Ramadan, as Allah tells us:

شهر رمضان الذى أنزل فيه القرآن

The month of Ramadan in which was revealed the Qur'an, (2:185) We have already quoted the relevant Hadiths in (the Tafsir of) Surah Al-Baqarah, and there is no need to repeat them here.

إنا كنا منذرين

Verily, We are ever warning. means, telling them what is good for them and what is harmful for them, according to Shariah, so that the proof of Allah may be established against His servants

فيها يفرق كل أمر حكيم