Al-Kāfi
Hadith 8218- أَحْمَدُ بْنُ مُحَمَّدٍ عَنْ عَلِيِّ بْنِ الْحَسَنِ عَنْ عَلِيِّ بْنِ أَسْبَاطٍ عَنِ الْحُسَيْنِ بْنِ زُرَارَةَ قَالَ سَأَلْتُ أَبَا عَبْدِ اللهِ (عَلَيْهِ السَّلام) عَنْ قَوْلِ اللهِ عَزَّ وَجَلَّ وَاذْكُرْ رَبَّكَ إِذا نَسِيتَ فَقَالَ إِذَا حَلَفْتَ عَلَى يَمِينٍ وَنَسِيتَ أَنْ تَسْتَثْنِيَ فَاسْتَثْنِ إِذَا ذَكَرْتَ.
8. Ahmad ibn Muhammad has narrated from Ali ibn al-Hassan from Ali ibn Asbat from al-Husayn ibn Zurarah who has narrated the following: “I once asked abu ‘Abd Allah (a.s.), about the meaning of the words of Allah, most Majestic, most Glorious, ‘. . . speak of your Lord if you forget.’ He (the Imam) said, ‘It is when you take an oath and forget to make the exception (saying if Allah so wills), then you must make the exception when you remember.’”