It is narrated from Sayyiduna Mu'adh bin Jabal (may Allah be pleased with him) that he said: We were travelling with the Messenger of Allah (peace and blessings be upon him) when the Messenger of Allah (peace and blessings be upon him) said: "Where are the forerunners?" The Companions said: Some people have gone ahead and some have stayed behind. He (peace and blessings be upon him) said: "Where are the forerunners who are devoted to the remembrance of Allah? Whoever would love to graze in the gardens of Paradise, let him remember Allah much." And this wording is from the hadith of Abdullah bin Umar bin Aban.
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 17462