Gita 02.69 explained
ya — what; nisa — is night; sarva — all; bhutanam — of living entities; tasyam — in that; jagarti — is wakeful; samyami — the self-controlled; yasyam — in which; jagrati — are awake; bhutani — all beings; sa — that is; nisa — night; pasyatah — for the introspective; muneh — sage.
What is night for all beings is the time of awakening for the self-controlled; and the time of awakening for all beings is night for the introspective sage.
Now this is a metaphorical verse.
ya nisa sarva-bhutanam, for all living being that which is Nisa, night, tasyam jagarti samyami, for the samyami, those who are regulated, that is the time of awakening, yasyam jagrati bhutani, and that which is the time for awakening for all living beings sa nisa pasyato muneh, that is the night for muneh.
So what Sri Krishna is talking about here?
Here Krishna is not talking about chronological or time based, clock based point of view or geographic things (like night in India and day in America), night here refers to period of inactivity, or lack of stimulation / interest and day refers to activities, interest etc. The activity of interest are different for materialistic and spiritualist. Sense gratification is activity of interest for materialist which is night for spiritualist they think it is Punha-Punah Charbita Charbananam, again and again chewing the chewed that is what we have enjoyed in several lower species and now we are enjoying that again in the human species, what is great about it human life is meant for something higher. So what is perceived as lot of interest for materialist spiritualist didn’t see a substance there.
What is day for spiritualist is self realization, chanting, read scripture, develop their relationship with Krishna and they get newer and newer happiness in that relationship with Krishna…this is incomprehensible for materistic, sit at one place and utter some sound for two hours. Like that you do for whole lifetime what you get out of it? So it is incomprehensible.
We can’t live and advance in spiritual life if we continue to live and hold material definition of success.
A devotee will be using the given talent in Krishna’s service and by doing so if we get success that is wonderful, we should do that, but that doesn’t mean that a devotee gets caught up in the same way as a materilist is, a devotees goal is not same as materialist his, goal is not fame but pream, love of Krishna, and as a loving offerings devotee also try to do wonderful things in Krishna’s service, but if our goal is material definition of success then we cannot make spiritual advancement.
When SP met Ambrish Ford grand son of Henry Ford he asked him ok you are the grand son of Henry Ford where he is now? So SP mean to say this material wealth is not eaternal.
Material people also have intelligence all these technological advancements requires the intelligence but they are divorced from ultimate reality that we are eternal beings and we need eternal happiness. So when SP tell those fools and rascals that is from spiritual perspective. We can appreciate their material intelligence but we can point them to the ultimate futility.
So the section was taking about Kim Vrajeta, how can one control his senses?
So after previous verse which says control all your senses, someone may say if we fully control our senses then what is the enjoyment available and what is the point of living such a life. So here spiritual enjoyment are different then material enjoyment we cannot impose material enjoyment on spiritual life. So there is different definition of enjoyment and that is the enjoyment we should perceive. So there are two classes of people who have two different definitions of enjoyment that is what this verse tells. And the sadhaka journey is to move from materialist definition of enjoyment to spiritual definition of enjoyment.