Surah Al-Baqarah, ayah 248

وَقَالَ لَهُمۡ نَبِيُّهُمۡ إِنَّ ءَايَةَ مُلۡكِهِۦٓ أَن يَأۡتِيَكُمُ ٱلتَّابُوتُ فِيهِ سَكِينَةٞ مِّن رَّبِّكُمۡ وَبَقِيَّةٞ مِّمَّا تَرَكَ ءَالُ مُوسَىٰ وَءَالُ هَٰرُونَ تَحۡمِلُهُ ٱلۡمَلَٰٓئِكَةُۚ إِنَّ فِي ذَٰلِكَ لَأٓيَةٗ لَّكُمۡ إِن كُنتُم مُّؤۡمِنِينَ ٢٤٨

Waqāla lahum nabiyyuhum inna āyata mulkihī an ya'tiyakumut-tābūtu fīhi sakīnatum mir rabbikum wabaqiyyatum mimmā taraka ālu mūsā wa ālu hārūna tahmiluhul-malā'ikatu inna fī dhālika la'āyatal lakum in kuntum mu'minīn

And their prophet said to them, "Indeed, a sign of his kingship is that the chest will come to you in which is assurance⁹⁷ from your Lord and a remnant of what the family of Moses and the family of Aaron had left, carried by the angels. Indeed in that is a sign for you, if you are believers."