Here is the commentary from The Study Quran on verse 4:48 —
“The sin of shirk, ascribing partners to God in worship or in His role as Creator, is considered to be the only sin God will not forgive (see also v. 116). Although this term is often associated with idolatry in the crass form of worshipping humanly constructed idols and indeed mushrikūn, the active participle from the same root, is often translated “idolaters” it can also refer to those who worship human authorities, false deities, angels (see 17:40c; 53:26 –27), jinn (6:100; 34:41), or natural phenomena (6:76 –78) as having independent influence and authority over the world or human destiny. The sin of shirk could also be broadened to include subtler ways of setting up “equals” with God, such as loving or fearing anything but God. The present verse compelled many to examine their own hearts and excise all such forms of “hidden shirk ” (Aj, Qu). Some say that this verse was revealed, in part, to clarify the assertion in 39:53 that God forgives all sins, making an exception for shirk ( Ṭ ). However, the possibility of forgiveness for shirk is precluded only for one who dies unrepentant (Z; see 67:10 –11c). The verse does not guarantee forgiveness for sins other than shirk, but allows for its possibility ( Ṭ ). ʿ Alī ibn Abī Ṭ ālib reportedly said that this verse gave him the greatest hope (Q), and Ibn ʿ Abbās considered it one of the eight most important verses about forgiveness (see 4:26 –28c). Some have seen this verse as a continuation of the warning issued to the Madinan Jews in v. 47 and even claim that it indicates that Jews can be considered mushrikūn, although this has never represented the general opinion among Muslim scholars. Nonetheless al-Rāzī argues syllogistically that since v. 47 warns that the Jews’ failure to believe in the message of the Quran will bring certain punishment, this failure to believe is de facto an “unforgivable sin”; since the only unforgivable sin is shirk, their failure to believe in the Quran is tantamount to shirk . However, this interpretation collapses the categories of shirk and kufr into one, whereas the two are distinct in the Quran and Islamic Law. In the Quran, Jews and Christians are clearly identified as religious practitioners separate from the mushrikūn (see 22:17; 98:1c), even if it sometimes suggests they might be guilty of something that approximates shirk (cf. 5:72; 9:30). In other places Jews and Christians are explicitly included in the category of “those who believe in God and the Last Day” and who may, therefore, enjoy a blessed Afterlife (2:62; 5:69). This clearly shows that Jews cannot be considered to be mushrikūn that is, those who take partners unto God in worship since that unforgiveable sin would necessarily bar them from such blessings in the Hereafter. This verse can also be read as a mitigation rather than an intensification of the threat to the Madinan Jews: if v. 47 threatens punishment for the Jews’ failure to believe in the Quranic message, v. 48 could be read as offering hope that all other sins perhaps even a failure to believe in the Quran and the Prophet on the part of the Jews (essentially kufr, or disbelief, but short of shirk ) are open to possible forgiveness. It is only shirk, theologically and legally distinct from kufr, that cannot be forgiven. Most early commentators read this verse as a general statement of hope to the believers concerning God’s willingness to forgive rather than as a particular threat to the Madinan Jews. Ibn ʿ Umar reports that upon the death of a fellow Muslim who he and others knew had committed a great sin, they bore witness that he was among the people of Hell. When this verse was revealed, they ceased to do so, as they realized that even great sins were open to Divine Forgiveness (Th).”
