9: And I say unto you, Ask, and it shall be given you; seek, and ye shall find; knock, and it shall be opened unto you. 10: For every one that asketh receiveth; and he that seeketh findeth; and to him that knocketh it shall be opened. 11: If a son shall ask bread of any of you that is a father, will he give him a stone? or if he ask a fish, will he for a fish give him a serpent? 12: Or if he shall ask an egg, will he offer him a scorpion? 13: If ye then, being evil, know how to give good gifts unto your children: how much more shall your heavenly Father give the Holy Spirit to them that ask him?

In verses 5-8 of Luke 11, the Bible has been showing us that we need a relationship with God the Father (in bed with Him). Now in Luke 9-13 the Bible is expanding on that relationship and telling us that God wants us to ask Him for things. He compares our relationship that we have with our children to the relationship that He has with His children (the Church/Us). He promises that if we ask, He will answer and give us good gifts. All the gifts that are mentioned are food items, and we know that God always relates the physical to the spiritual, so these food items represent spiritual food that we need.
Physical Bread Spiritual Bread = The Bible – God’s Word
Physical Fish  Spiritual Fish = A person who needs the Word
Physical Egg  Spiritual Egg = The Holy Spirit who teaches the Word
So God the father wants us to be able to receive His Word (the Bible) and to ask for the Holy Spirit to teach us His Word. We know that Jesus is God’s Son (the Father’s Son) and that Jesus asked His father to send the Holy Spirit to His disciples. John 14:16-17 And I will pray the Father, and he shall give you another Comforter, that he may abide with you for ever; Even the Spirit of truth; whom the world cannot receive, because it seeth him not, neither knoweth him: but ye know him; for he dwelleth with you, and shall be in you. So just as we would respond to our son asking us for physical food (bread/fish/egg), God, our Father, will respond to us when we ask for spiritual food (to understand the Bible) and to have the Holy Spirit teach us when we pray.