Whereas Matthew's account has Jesus saying, “I will keep the Passover at your house with My disciples” (Matthew 26:18), Mark's clarifies the phrase “keep the Passover” with “eat the Passover.” This is an essential detail because some have tried to explain His words away by claiming He merely mentions preparing for the Passover. But Mark brings out the fact that on this same occasion He meant He would eat the Passover with His disciples, not simply make preparations.
We again see His intention to use the guest (or upper) room of that certain man's house. Did our Messiah mean what He said? Are any words of God untrustworthy? If He did not mean what He said here, it means that either the sovereign God's will was thwarted, or else Jesus duplicitously said one thing while intending to do another. As Paul says, God forbid!