Mark 2:23-28 and Hebrews 6:10-20

Mark 2:23-28
As Jesus was passing through a field of grain on the sabbath,
his disciples began to make a path while picking the heads of grain.
At this the Pharisees said to him,
"Look, why are they doing what is unlawful on the sabbath?"
He said to them,
"Have you never read what David did
when he was in need and he and his companions were hungry?
How he went into the house of God when Abiathar was high priest
and ate the bread of offering that only the priests could lawfully eat,
and shared it with his companions?"
Then he said to them,
"The sabbath was made for man, not man for the sabbath.
That is why the Son of Man is lord even of the sabbath."
Hebrews 6:10-20
Brothers and sisters:
God is not unjust so as to overlook your work
and the love you have demonstrated for his name
by having served and continuing to serve the holy ones.
We earnestly desire each of you to demonstrate the same eagerness
for the fulfillment of hope until the end,
so that you may not become sluggish, but imitators of those who,
through faith and patience, are inheriting the promises.

When God made the promise to Abraham,
since he had no one greater by whom to swear, he swore by himself,
and said, I will indeed bless you and multiply you.
And so, after patient waiting, Abraham obtained the promise.
Now, men swear by someone greater than themselves;
for them an oath serves as a guarantee
and puts an end to all argument.
So when God wanted to give the heirs of his promise
an even clearer demonstration of the immutability of his purpose,
he intervened with an oath,
so that by two immutable things,
in which it was impossible for God to lie,
we who have taken refuge might be strongly encouraged
to hold fast to the hope that lies before us.
This we have as an anchor of the soul,
sure and firm, which reaches into the interior behind the veil,
where Jesus has entered on our behalf as forerunner,
becoming high priest forever
according to the order of Melchizedek.

http://www.usccb.org/bible/readings/011717.cfm