Translation:

131. But when good (times) came they said "this is due to us"; when gripped by calamity they ascribed it to evil omens connected with Moses and those with him! Behold! in truth the omens of evil are theirs in Allah's sight but most of them do not understand!

Notes (Tafseer)

1088. Their superstition ascribed the punishment of their own wickedness to some evil omen. They thought Moses and his people brought them ill-luck. They did not look within themselves to see the root of evil, and the cause of their punishment! So it happens in all ages. People blame the righteous for something which they do, different from other men, instead of searching out their own lapses from rectitude, which are punished by Allah.