> أَرَءَيۡتَ ٱلَّذِي يُكَذِّبُ بِٱلدِّينِ 
(107:1)
> 
>Have you seen the one who denies the recompense?

> وَرَأَيۡتَ ٱلنَّاسَ يَدۡخُلُونَ فِي دِينِ ٱللَّهِ أَفۡوَاجٗا 
(110:2)
>
>And you have seen mankind entering into Allah's religion in crowds. 



In (110:2), the first word is وَرَأَيۡتَ and the hamzah has an alif for a seat.  

In (107:1), the first word is أَرَءَيۡتَ but now the corresponding hamzah has no seat - that is, it's drawn directly on the line.

Why is this word written differently in these two ayahs, when it's the same verb, and the exact same tense, voice, person, gender and number?  That is, it's second person masculine singular past active, so the conjugation is the same (i.e. the suffix تَ) in both ayahs.