﴿ وَلَوْ أَلْقَىٰ مَعَاذِيرَهُۥ ﴾

“even though he may veil himself in excuses.”

though he should offer his excuses ma‘ādhīr is the plural of ma‘dhira but following a different pattern from the usual ma‘dhira ma‘ādhir that is to say whatever excuse he offers will not be accepted from him.