Allah replied to this false claim,

[قُلْ]

(Say), O Muhammad, to those who claimed this,

[إِنَّ اللَّهَ لاَ يَأْمُرُ بِالْفَحْشَآءِ]

("Nay, Allah never commands Fahsha'...'') meaning, the practice you indulge in is a despicable sin, and Allah does not command such a thing.

[أَتَقُولُونَ عَلَى اللَّهِ مَا لاَ تَعْلَمُونَ]

("Do you say about Allah what you know not'') that is, do you attribute to Allah statements that you are not certain are true Allah said next,

[قُلْ أَمَرَ رَبِّي بِالْقِسْطِ]

(Say: "My Lord has commanded justice, (fairness and honesty)''),

[وَأَقِيمُواْ وُجُوهَكُمْ عِندَ كُلِّ مَسْجِدٍ وَادْعُوهُ مُخْلِصِينَ لَهُ الدِّينَ]

("And that you should face Him only, in every Masjid, and invoke Him only making your religion sincere to Him...'') This Ayah means, Allah commands you to be straightforward in worshipping Him, by following the Messengers who were supported with miracles and obeying what they conveyed from Allah and the Law that they brought. He also commands sincerity in worshipping Him, for He, Exalted He is, does not accept a good deed until it satisfies these two conditions: being correct and in conformity with His Law, and being free of Shirk.