"lāy sajīvan lakhan jiyāye" is Chaupai 11 of the Hanuman Chalisa, which Tulsidas wrote in Awadhi. It means: You brought the sanjivani herb and revived Lakshmana. Rama, hero of the Raghus, held you to his heart with joy. Read it slowly, one half at a time, and say the Awadhi aloud.
When Lakshmana falls in battle, the physician Sushena names the herb on the mountain and Hanuman goes for it. When he returns, the Manas says Rama embraced Hanuman with joy, the words this line echoes.
राम पदारबिंद सिर नायउ आइ सुषेन। कहा नाम गिरि औषधी जाहु पवनसुत लेन॥
Ramcharitmanas, Lanka Kand 6.55, doha 1
हरषि राम भेंटेउ हनुमाना। अति कृतग्य प्रभु परम सुजाना॥
Awadhi text: Goswami Tulsidas, Gita Press reading, checked against three Gita Press printings and Rambhadracharya's Mahaviri. English meaning and word glosses: Wisdom's own, following the traditional reading, edited by Ankur Shukla.