Are you pulling money out of your 401k? Are you pulling money out of your VTSAX?
These questions as paired together do not make sense. "VTSAX" is an investment fund, not an account -- they are separate and orthogonal concepts. In fact, depending on the fund choices available it is possible for your 401k to be invested in VTSAX so that the answer to both questions could be "yes" at the same time!
First, you need to figure out what
accounts you have (taxable account, traditional 401k and/or IRA, Roth 401k and/or IRA, HSA, etc.) and then figure out what
investments (stock index funds, bond index funds, balanced/target date funds, individual stocks, individual bonds, money-market/cash, etc.) you have
inside each of those accounts.
Then, you decide what to withdraw based on (a) the tax characteristics of the account type, (b) the performance of the investment type and the effect withdrawing it will have on your asset allocation, and (c) the tax characteristics of the investment type (e.g. capital gains on stocks vs. ordinary income from bonds) if held in a taxable account.