40a For explanation, see (E.N. 26).
41. Abid is worshiper. According to the Arabic usage, to be a worshiper and a bondsman are almost synonymous. Therefore when the Prophets invited their people to worship Allah alone, they wanted them to worship and serve and obey none but Allah, and that is the real significance of the word ibadat. For further explanation, see (E.N. 50 of Surah Al-Kahf).