Al-Baqarah 2:248

And their prophet said to them, after they had demanded a sign of his kingship: ‘The sign of his kingship is that there will come to you the Ark, a chest containing the images of the prophets, which God sent down to Adam, and which was handed down to them [sc. the Israelites], until the Amalekites seized it from them in battle. They used to commence fighting invoking it before their enemy and marching behind it, as well as experience peacefulness in its presence, as God says: therein is a Spirit of Peace, reassurance for your hearts, from your Lord, and a remnant of what the folk of Moses and the folk of Aaron left behind, which were Moses’s pair of sandals and his staff, Aaron’s turban, a measure (qafīz) of the manna that used to come down on them, and the pieces of the broken tablets, the angels bearing it (tahmiluhu l-malā’ikatu, the circumstantial qualifier referring to the subject of the verb ya’tiyakum, ‘there will come to’). Surely in that shall be a sign for you, of his kingship, if you are believers’. The angels bore it between the earth and the sky while they gazed at it, until finally they placed it before Saul. They then acknowledged his kingship and hastened to enlist in the [holy] struggle, and he chose seventy thousand of their young men.