Here’s Matthew 12:46-50:
46While he yet talked to the people, behold, his mother and his brethren stood without, desiring to speak with him.
47 Then one said unto him, Behold, thy mother and thy brethren stand without, desiring to speak with thee.
48 But he answered and said unto him that told him, Who is my mother? and who are my brethren?
49 And he stretched forth his hand toward his disciples, and said, Behold my mother and my brethren!
50 For whosoever shall do the will of my Father which is in heaven, the same is my brother, and sister, and mother.
Wonder why Jesus’ sister suddenly makes an appearence in verse 50? She doesn’t. She’s been there all along. She was just hiding behind a plural noun ending. Like many other languages, Greek follows these rules:
when a noun refers to more than one woman, use the plural feminine ending
when a noun refers to more than one man, use the plural masculine ending
when a noun refers to a mixed-gender group, use the plural masculine ending
In this case it is clear that every time ‘brethren’ is used, it meant ‘brothers and sister,’ but only because of the fluke in the verse 50–the fact that Jesus changes to the singular forms from the plural. In most situations, we have no clear indication whether a word such as ‘brethren,’ ‘disciple,’ or ‘men’ includes women. One Greek word, aner, specifically means ‘male’ and is therefore unlikely to have women hiding in it; some scholars argue otherwise, but I think they are trying too hard to find what they want. But another word, anthropos, is translated in the KJV as ‘men’ although is more akin to our ‘people.’ Anthropos is more than twice as common in the NT as aner, and awareness of alternative options for translating it may affect how we read such verses as Matthew 9:8.
This is a reminder that women are sometimes present in the story of Jesus’ life when we don’t expect it. Look for them.