In Catholic circles you will often hear the term "last rites." Even among Catholics, it is often confused with the Anointing of the Sick.
Of all of the sacraments it may be the most misunderstood. It is not intended to be given en masse to whole groups of people who might have a cold, as happens in some places. This only trivializes the sacrament.
It is not given to children who have not yet reached the age of reason, because it brings with it the remission of sin, which they could not have committed.
The anointing of the sick "can be administered to a member of the faithful who, having reached the use of reason, begins to be in danger due to sickness or old age." It is worth noting that the sickness is not specified it could be physical or mental. Most important is the word "begins."
It is not our belief that one should wait until they are at death's door. From the moment one is diagnosed with life-threatening illness, the sacrament is there to provide spiritual strength, and can be repeated. Anytime one is being put under general anesthetic there is danger, and so I encourage those going into for surgery to request the sacrament. And as the law says, old age in itself can put one in danger of death. Because it involves spiritual healing, the remission of sin it can only be given by a priest or bishop.
The sacrament of Anointing comes from James 5:14
"Is anyone among you sick?* He should summon the presbyters of the church, and they should pray over him and anoint [him] with oil in the name of The Lord"
What does this have to do with our reading today from exodus?
Here we get to "last rites." The church does in fact have a ritual for those who are preparing to make the final journey to the true promised land, heaven. This rite involves more than anointing, but also the sacrament of penance, and a final reception of communion, if possible. The term for this final reception of communion comes straight from today's first reading.
Today's first reading tells us that the Israelite baked unleavened bread and took it as "food for the journey." For us as Christians, the food for the journey is the Eucharist. In Latin we call it viaticum.
So there are two different things in the Catholic Church. One is in fact still Last Rites. The other is the Anointing of the Sick.