﴿ لِمَن شَآءَ مِنكُمْ أَن يَتَقَدَّمَ أَوْ يَتَأَخَّرَ ﴾

“to everyone of you, whether he chooses to come forward or to hang back!”

(Unto him of you who will advance) towards goodness (or hang back) from evil and therefore holds back from it; it is also said this means: or hang back from goodness and therefore disbelieve; this being a threat to them.