Surah 17. Al-Israa, Ayah 11

This, to my mind, is the meaning of the conjunctive particle wa in the above context.

Cf. {2: 216} - "it may well be that you hate a thing the while it is good for you, and it may well be that you love a thing the while it is bad for you: and God knows, whereas you do not know": in other words, divine guidance is the only objective criterion as to what is good and what is bad.

 Some people are quick to pray against themselves or others in times of anger and frustration.

Man in his ignorance or haste mistakes evil for good, and desires what he should not have. The wise and instructed soul has patience and does not put its own desires above the wisdom of Allah. He receives with contentment the favours of Allah, and prays to be rightly guided in his desires and petitions.