سُورَةُ التَّوۡبَةِ

Had there been [a prospect of] immediate gain, and an easy journey, they would certainly have followed thee, [O Prophet:] but the distance was too great for them. And yet, [after your return, O believers,] they will swear by God, "Had we been able to do so, we would certainly have set out with you!" - [and by thus falsely swearing] they will be destroying their own selves: for God knows indeed that they are lying!