“Pilgrimage to the House (of Allah) is a duty man owes to Allah upon those who can afford the journey.”
The ulama inform us that Hajj became obligatory when this verse was revealed. When we look at the verse we see a lot of emphasis and stress. Let us study it:
Firstly, we find a Laam on the word of Allah (Lillaahi) which lays emphasis on the fact that Hajj is obligatory. (see Allama Ainy)
‘Alan-naas’ is another term that denotes extreme emphasis.