What does « To climb / To limp » mean in the Quran?

And [even] if We opened to them a gate from the heaven and they continued therein to ascend,

There is not upon the blind [any] constraint nor upon the lame constraint nor upon the ill constraint nor upon yourselves when you eat from your [own] houses or the houses of your fathers or the houses of your mothers or the houses of your brothers or the houses of your sisters or the houses of your father's brothers or the houses of your father's sisters or the houses of your mother's brothers or the houses of your mother's sisters or [from houses] whose keys you possess or [from the house] of your friend. There is no blame upon you whether you eat together or separately. But when you enter houses, give greetings of peace upon each other - a greeting from Allah, blessed and good. Thus does Allah make clear to you the verses [of ordinance] that you may understand.

He arranges [each] matter from the heaven to the earth; then it will ascend to Him in a Day, the extent of which is a thousand years of those which you count.

He knows what penetrates into the earth and what emerges from it and what descends from the heaven and what ascends therein. And He is the Merciful, the Forgiving.

And if it were not that the people would become one community [of disbelievers], We would have made for those who disbelieve in the Most Merciful - for their houses - ceilings and stairways of silver upon which to mount