Dreaming of a deceased parent, such as your father, can be a powerful and emotional experience. This type of dream often represents unresolved feelings, longing, or the need for closure. The phrase "it took a lot of effort to reach here" may indicate that you are reflecting on the challenges or struggles you've faced in your life or in your relationship with him.

Here are a few possible interpretations:

1. Seeking Guidance: Your father's presence in your dream may suggest that you are looking for guidance or support during a difficult time. It could be your subconscious seeking wisdom from his past teachings.
2. Processing Grief: This dream might be a part of your grieving process. It could indicate that you are working through feelings of loss and the effort it takes to cope with his absence.
3. Personal Growth: The effort mentioned may symbolize your journey towards personal growth or overcoming obstacles in your life. Your father's acknowledgment of the effort could reflect your own recognition of the hard work you've put into your life or personal development.
4. Communication Beyond Life: Some believe that dreams of deceased loved ones can serve as a means of communication. Your father's message might signify his understanding of your struggles and a reminder to continue persevering.

Consider how you felt during the dream and any significant events in your life that may relate to these themes. Reflecting on these aspects can provide further insight into the personal meaning of this dream for you.