Why can ether molecules not form hydrogen bonds with one another?

Ether molecules cannot form hydrogen bonds with one another because they lack the necessary hydroxyl groups found in alcohols.1

A hydrogen bond requires both a hydrogen atom attached to a highly electronegative atom (such as oxygen, nitrogen, or fluorine) to act as a donor, and a suitable acceptor atom with a lone pair of electrons. In an ether molecule, the oxygen atom is bonded to two alkyl or aryl groups rather than a hydrogen atom. Because there is no strongly polarized O—H bond present, ether molecules cannot engage in hydrogen bonding with each other.21

While they cannot bond with themselves, ethers do possess nonbonding electron pairs on their oxygen atoms, which allows them to form hydrogen bonds with other molecules that contain O—H or N—H bonds.1