Sutra:
279. vEdha purushan upAyAntharangaLai vidhiththadhu koNdip pasuvukkuth thadi katti vidivAraip pOlE ahankAra mamakArangaLAl vandha kaLippaRRu svarUpajnAnam piRakkaikAga.

Sri PBA Swami's Sarartha Deepikai:
Lord Krishna might have explained the other paths to test Arjuna's heart. But why did the Lord of the Vedas do the same in the Vedas - that is, why are the other paths shown as paths to mOksha in the Vedas?

An example is used here: There is a cow that does not stay under the control of it owner and always grazes at every place that it is not supposed to. So, the owner ties a big stick to its neck which hangs low. So, every time the cow tries to run away, the stick would hit its legs and would slow it down. This would prevent the cow from taking off to places where it is not supposed to go.

Similarly, the chetana too enjoys many things coming out of his ahankAra and mamakAra. In order to remove this enjoyment and make the chetana realize his true nature (of being completely dependent on Him), the Veda purusha prescribed the other paths.