I intended to go (on expedition) to Khaybar. So I came to the Holy Prophet ﷺ, greeted him and said: I am intending to go to Khaybar. He said: When you come to my agent, you should take from him fifteen wasqs (of dates). If he asks you for a sign, then place your hand on his collar-bone.  

أَرَدْتُ الْخُرُوجَ إِلَى خَيْبَرَ فَأَتَيْتُ رَسُولَ اللَّهِ ﷺ فَسَلَّمْتُ عَلَيْهِ وَقُلْتُ لَهُ إِنِّي أَرَدْتُ الْخُرُوجَ إِلَى خَيْبَرَ فَقَالَ إِذَا أَتَيْتَ وَكِيلِي فَخُذْ مِنْهُ خَمْسَةَ عَشَرَ وَسْقًا فَإِنِ ابْتَغَى مِنْكَ آيَةً فَضَعْ يَدَكَ عَلَى تَرْقُوَتِهِ