How to Cross Samsara by a Meditation Object?

The venerable Upasiva once requested the
Buddha:
Sir, I am alone, dependent, helpless, I can neither cross the flood of sense
desire,
nor the flood of becoming, nor the flood of ignorance, nor the flood of views!
Please, All-Seeing-One, tell me the meditation object by which, I may cross this
flood.
Aware, direct mind towards Nothingness,
replied the Buddha, be helped by relying on the
notion: 'Nothing really is...'! Thus by relinquishing all desires, by stilling
all speculative opinions,
and by reviewing the elimination of craving day and night, you may cross this flood...!


Crossing into Nothingness...
Source:
Sutta Nipāta 1069-70
https://what-buddha-said.net/library/ati_website/html/tipitaka/kn/snp/snp.5.06.than.html