Imam Ahmad recorded from Abu Hurayrah that the Prophet said:

«صَلُّوا عَلَيَّ، فَإِنَّهَا زَكَاةٌ لَكُمْ، وَسَلُوا اللهَ لِيَ الْوَسِيلَةَ، فَإِنَّهَا دَرَجَةٌ فِي أَعْلَى الْجَنَّةِ، لَا يَنَالُهَا إِلَّا رَجُلٌ، وَأَرْجُو أَنْ أَكُونَ أَنَا هُو»

(Send Salah upon me, for this is Zakah for you, and ask Allah to grant me Al-Wasilah, for it is a position in the highest part of Paradise which only one man will attain, and I hope that I will be the one.) This was recorded only by Ahmad.