Tafseer : At-Tawbah 42

Allah admonishes those who lagged behind and did not join the Prophet for the battle of Tabuk, those who asked the Prophet for permission to remain behind, falsely pretending to have legitimate reasons to do so,

Had it been a near gain

booty right in front of them, according to Ibn `Abbas,

and an easy journey

travel for only a short distance,

they would have followed you

But,

the distance was long for them

to Ash-Sham,

and they would swear by Allah

when you return to them,

If we only could, we would certainly have come forth with you

had not there been a valid excuse, we would have gone out with you,

They destroy themselves, and Allah knows that they are liars.