"Saadar tum" instead of "Sada raho" in Hanumaan Chaalisa

During recitation of the Hanumaan Chaalisa, many people are heard to be speaking:

Raam rasayan tumhre paasa,
Sadaa raho raghupati ke daasa.

which appears to be an order being given to Shri Hanumaan to remain a devotee to Shri Raam.

Around 15 years ago, I read the following lines instead of the above mentioned ones for shlok no. 32 in a Hanumaan Chaalisa book:

Raam rasayan tumhre paasa,
Saadar hey raghupati ke dasaa.

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Jai Shree Hanumaan.
Jai Shree Raam.