Tafsir of Al-Qamar 54:5

حكمة بالغة

Perfect wisdom, in that Allah guides whomever He wills and misguides whomever He wills,

فما تغن النذر

but warners benefit them not. but the preaching of warnings does not benefit those upon whom Allah has written misery and sealed their hearts. Who can guide such people after Allah? This Ayah is similar to Allah's statements,

قل فلله الحجة البلغة فلو شاء لهداكم أجمعين

Say: "With Allah is the perfect proof and argument; had He so willed, He would indeed have guided you all.'' (6:149) and,

وما تغنى اﻻيت والنذر عن قوم ﻻ يومنون

But neither Ayat nor warners benefit those who believe not. (10:101)