Ibn Kathir reported: Imam Ahmad ibn Hanbal, may Allah have mercy on him, was asked about the existence of the Creator. Ahmad said, “Consider an impenetrable fortress without any doors or exits. The outside is like white silver and the inside is like shimmering gold. It is built like this until its walls crack and out comes an animal hearing and seeing with a beautiful shape and a pleasant voice.” Ahmad meant by that an egg when the chick comes out of it.
Source: Tafsīr Ibn Kathīr 2:21
عن ابن كثير وَعَنِ الْإِمَامِ أَحْمَدَ بْنِ حَنْبَلٍ رحمه الله أَنَّهُ سُئِلَ وُجُودِ الصَّانِعِ فَقَالَ هَاهُنَا حِصْنٌ حَصِينٌ أَمْلَسُ لَيْسَ لَهُ بَابٌ وَلَا مَنْفَذٌ ظَاهِرُهُ كَالْفِضَّةِ الْبَيْضَاءِ وَبَاطِنُهُ كَالذَّهَبِ الْإِبْرِيزِ فَبَيْنَا هُوَ كَذَلِكَ إِذِ انْصَدَعَ جِدَارُهُ فَخَرَجَ مِنْهُ حَيَوَانٌ سَمِيعٌ بَصِيرٌ ذُو شَكْلٍ حَسَنٍ وَصَوْتٍ مَلِيحٍ يَعْنِي بِذَلِكَ الْبَيْضَةَ إِذَا خَرَجَ مِنْهَا الدَّجَاجَةُ
2:21 تفسير القرآن العظيم سورة البقرة قوله تعالى يا أيها الناس اعبدوا ربكم الذي خلقكم