عَنْ إِسْحَاقَ بْنِ غَالِبٍ عَنْ أَبِي عَبْدِ اللهِ عَلَيْهِ السَّلَامُ قَالَ عَبَدَ اللهَ حَبْرٌ مِنْ أَحْبَارِ بَنِي إِسْرَائِيلَ حَتَّى صَارَ مِثْلَ الْخِلَالِ فَأَوْحَى اللهُ عَزَّ وَ جَلَّ إِلَى نَبِيِّ زَمَانِهِ قُلْ لَهُ وَ عِزَّتِي وَ جَلَالِي وَ جَبَرُوتِي لَوْ أَنَّكَ عَبَدْتَنِي حَتَّى تَذُوبَ كَمَا تَذُوبُ الْأَلْيَةُ فِي الْقِدْرِ مَا قَبِلْتُ مِنْكَ حَتَّى تَأْتِيَنِي مِنَ الْبَابِ الَّذِي أَمَرْتُكَ
Is’haaq Ibn Ghaalib reports that Imam Abu Abdillah (al-Sadeq) (peace be on him) informed, “A scholar from the scholars of the Bani Israel worshipped Allah till he became like a tooth-pick (i.e. very thin due to excessive worship). So Allah – Mighty and Majestic be He – revealed to a Prophet of his time, ‘Tell him, ‘By My Mighty, My Majesty and My Power! Even if you worship Me till you melt like fat melts in a cooking pot, I will not accept from you till you approach Me from the door which I have ordered you’.”
References:
1. Sawaab al-A’maal, p. 203
2. Behaar al-Anwaar, vol. 27, p. 176, H. 23
3. A’laam al-Deen, p. 400
4. Mustadrak al-Wasaael, vol. 1, p. 156, Chapter 27, p. 245