Imam Muhammad al-Busiri [d.695 AH] says in his al-Burdah (The Prophetic Eulogy):
And contradict both the Self and Devil, and disobey!
And if they give true advice to you, still look sceptically.
Imam Ibrahim al-Bajuri [d. 1277 AH] said in explanation of the verses mentioned above [Sharh al-Burdah pg. 31-32]:
His (Busiri’s) words, “And contradict both the Self and Devil“, meaning if your Self and Devil order you with a matter, or your Self or Devil forbid you from a matter, then oppose them for they both are your enemy.
His words, “and disobey” (them both), indicate that it is not sufficient to merely oppose them—because one may oppose them to that which they both are pleased with—rather it is necessary to disobey them.
The author preceded the mention of the Self before the Devil because the Self is more harmful than the Devil; its tribulation is greater than the Devil’s tribulation. This is because the Self is an enemy in the form of a friend and a person is not aware of the plots of a friend. Also, it is an enemy from within, as opposed to the Devil for he is a clear enemy. And it is said, “Escaping from the Self is the greatest blessing, because it is the greatest veil between a person and Allah ﷻ”.
Sahl bin Abdullah said, “Allah has not been worshipped with a thing like the opposing of the Self and desire”.
So generally, the opposing of the Self is the peak of worship and the first of the levels of felicity. Look to the action of the Devil with your father (Adam)! The Devil swore that he was a sincere advisor to him, yet how is he with you when he has sworn to misguide you?
His words, “And if they give true advice to you, still look sceptically”, meaning if they both offer you advice, such as; they both say to you, ‘Fulfil this desire so that you may focus towards obedience with an untroubled heart’; or they both say to you, ‘Be gentle with yourself in worship so that you are able to be consistent in it’, or to increase your worship so as to attain high ranks or its like. Be sceptical of them by attributing treachery to them, because nothing emanates from them except deception. Thus it is said, ‘Devil opens ninety-nine doors of good for a person so as to land him in one door of evil’.
The speciality of this verse, as well as the one after it, is that the one who is persistent in its (recitation) will overcome his Self and his Devil, and will be granted protection by Allah from them both, Allah willing.
Source: Karima Foundation