R. Israel Baal Shem [Tov], peace be upon him, said:

“Make a light for the teivah (ark) [and finish it to (the width of) an amah (cubit) on high . . .].” (Genesis 6:16) This means that the teivah (word) 1 should shine. [This will be understood by the following:]

Every letter contains “worlds, souls and Divinity.” 2 These ascend and become bound up and united with one another, with Divinity. The letters then unite and become bound together to form a word [teivah], becoming truly unified in Divinity. Man, therefore, must include his soul in each of these aspects. 3 All worlds will then be unified as one and ascend, and this effects immeasurably great joy and delight. 4

This is the meaning of “[make it with] bottom, second and third [stories]” (ibid.), referring to “worlds, souls and Divinity;” 5 [for “The Holy One, blessed is He,] has three worlds [in which He is concealed]” (Zohar III:159a 6).

With every word you must hear what you say, because it is the Shechinah [Herself], the “World of Speech,” who speaks, 7 provided that [the word] has a “light,” i.e., that it emerges with brightness 8 and to bring gratification to your Maker. This requires great faith, as the Shechinah is referred to as “true faithfulness” (Isaiah 25:1; see Zohar I:22a and III:16b). 9 Without faith, it is, Heaven forbid, a case of “he that murmurs separates the Master [of the universe].” (Proverbs 16:28) 10

[The concluding phrase] “finish it to an amah (cubit) on high” means “to imah (the ‘mother’).” 11

Alternatively one can interpret as follows:

Once the word has left your mouth there is no need to mind it any more. That is, one does not see it ascend to the higher realm, just as one is not able to look at the sun. This is the meaning of “finish it on high.” 12

One can achieve this by “Come into the teivah, you with all your family” (Genesis 7:1), i.e., with all of your body and strength. 13