Allah says,

(Have We not opened your breast for you) meaning, `have We not opened your chest for you.' This means, `We illuminated it, and We made it spacious, vast and wide.' This is as Allah says,

(And whomsoever Allah wills to guide, He opens his breast to Islam.) (6:125) And just as Allah expanded his chest, He also made His Law vast, wide, accommodating and easy, containing no difficulty, hardship or burden.