أَفَلَا يَتُوبُونَ إِلَى ٱللَّهِ وَيَسْتَغْفِرُونَهُۥ ۚ وَٱللَّهُ غَفُورٌ رَّحِيمٌ
Afalaa yatooboona ilal laahi wa yastaghfiroonah; wallaahu Ghafoorur Raheem
Will they not turn back to God and seek his forgiveness? God is forgiving, merciful.
An invitation to return arrives in the middle of the surah's sharpest doctrinal argument, directly after the warning of painful punishment for those who call God the third of three. The question form, afalā yatūbūna, asks why they have not yet come back, and the verse closes on forgiveness and mercy before the argument about the Messiah resumes. Placing the offer there keeps repentance available to exactly the people the passage has been warning.