Rain is one of the 𝙫𝙞𝙗𝙝𝙪𝙩𝙞 (glimpses) of the 𝙋𝙖𝙧𝙖𝙢𝙖𝙩𝙢𝙖 and the blessings (water) are harvested by the wise by keeping their bowl upright. Further, the wise realise the 𝙋𝙖𝙧𝙖𝙢𝙖𝙩𝙢𝙖 once they see any 𝙫𝙞𝙗𝙝𝙪𝙩𝙞 (like rain) and Krishna calls this realisation 'uniting with HIM'. These glimpses include intellect, knowledge, freedom from doubt, forgiveness, truthfulness, control over the senses and mind, joy and sorrow, birth and death, fear and courage, non-violence, equanimity, contentment, austerity, charity, fame, and infamy (10.4 and 10.5). Incidentally, a whole lot of literature on leadership and management revolves around these glimpses. At the core it is being positive and seeing HIM in both good and bad; in both our likes and dislikes.
Krishna says that those who know the truth (𝙩𝙖𝙩𝙫𝙖) of My 𝙫𝙞𝙗𝙝𝙪𝙩𝙞 (glimpses of glories) and divine powers (𝙮𝙤𝙜𝙖-𝙨𝙝𝙖𝙠𝙩𝙞) become united with Me through unwavering devotion. Of this, there is no doubt (10.7). Krishna uses the word ' 𝙩𝙖𝙩𝙫𝙖 ' to reflect 'knowing' the truth at the existential level and not mere memorisation. This realisation leads to the dropping of divisions and bringing unity which is becoming one with 𝙋𝙖𝙧𝙖𝙢𝙖𝙩𝙢𝙖 .
Many times Krishna comes to the level of Arjun to explain things in Arjun's frame of reference and in terms of the understanding of his time. Referring to Arjun's understanding of evolution, Krishna says, "The seven great Sages, the four great Saints before them, and the fourteen Manus, are all born from My mind. From them, all the people in the world have descended" (10.6).
Krishna further says, "I am the origin of all creation. Everything proceeds from Me. The wise who know this perfectly worship Me with great devotion" (10.8). In a nutshell, HE is the origin whether it was Arjun's understanding that we came from seven sages or today's prevailing understanding of the Big Bang as our origin.