وَرَأَيْتَ النَّاسَ يَدْخُلُونَ فِي دِينِ اللَّهِ
And you see people entering Allah's religion. (110:2)
Yadkhulūn is an indicative imperfect with the plural subject suffix. Under a standard analysis, the whole verb clause is a circumstantial sentence describing al-nās. It tells us not merely that people are seen, but the condition in which they are observed.
There is no separate circumstantial wāw before yadkhulūn. An affirmative imperfect can form a ḥāl without that wāw, while its plural pronoun supplies the link back to the people described.